Electrical switch



H. R. STEVENS AND R. L. ROCKWELL. ELECTRICAL SWITCH} APPLICATION HLED JUNE 12. 1912.

1,345,899 Patented July 6, 1920.

INVENTQRD 90551; L OCKWE L HENBY a STCVEN$ "posite direction.

"UN I TED S TA T E S P A TE NT OFFI'C E HENRY R. STEVENS AND ROBERT L. RQCKWELL, or SEATTLE, WASHINGTON,

ASSIGNCRS ro WASHINGTON.

ELECTRICAL SWITCH.

To all whom it may concern:

Be 1t known that we, HENRY R. STEVENS and ROBERT L. ROCKWELL, Citizens of the United States, residing at Seattle, in the county of King and State of lVashington, have invented a new and useful Improvement inElectrical Switches, of the class commonly termed limitsWitcheS, of which the following is a specification.

This invention relates to improvements in electrical switches of the class commonly termed limit switches, and is especially adapted for use in connection with the electrical control system for railway track sections, illustrated and described in our c0- pendingapplication of even date herewith.

The object of this improvement is to provide a switch of this nature that is simple in its form of construction and reliable in its operation.

A further object is to provide a limit switch that will make a contact between one set of switch terminals at the sametime that it breaks the Contact between another set of switch terminals. Y 7 A still further object is to provide a limit switch of this class that will make a momentary electrical contact when it is thrown in one direction but will not make a similar momentary contact when thrown in the op- In the accompanyingdrawings, Figure 1 is plan view ofa limit switch constructed in accordance with this invention, and Fig. 2 is a view in side elevation of the device shown in Fig. 1. i p

Referring to the drawings, throughout which like reference numerals indicate like parts, the numeral 5 indicates a base or Support for the switch mechanism.

Mounted on the base 5 adjacent one side thereof are a plurality of U-shaped terminals 6 that are adapted for the reception of switch blades 7, and mounted in a similar manner adjacent the opposite side of the base 5 are a plurality of similar terminals 8 adapted for the/reception ofsw'i'tch blades 10. The switch blades 7may beintegral with the switch blades 10 and disposed at an angle thereto so 'thatfwhen the Switch blades 10 are inncontact with the terminals 8, as "shown in Fig. 2, the switch'blades 7 Specification of Letters Patent.

UNIVERSAL ELEVATED RAILVTAY COMPANY, OF SEATTLE,

Patented July 6, 1920.

1918. Serial No. 239,675.

will be out of contact with the terminals 6, the switch blades 7 and 10 being medially pivoted in brackets 11. i

The outer ends of the switch blades 7 are preferably all connected together by a bar of insulating material 12 and outer ends of the switch blades 10 are connected in the same manner by a similar bar of insulating material 13 so that the blades will all move .simulta neously.

The devices for making and breaking contacts between the switch blades 7 and the terminal 6 and the switch blades 10 and the terminal 8 comprise a frame 14, the lower end of which is pivotally mounted on a bolt 15 so that it may be swung fromthe posi tion shown by full lines to the position shown by dotted lines in Fig. 2. Within the upper portion of the frame 14 is provided. a race or run-way 16 within which is disposed a relatively heavy cylindrical member 17 that is adapted to run from one end of the race 16 to the other as the frame 14 passes the vertical position The cylindrical member 17 thus serves to complete the throwing of the switch after it has been partly thrown by other "means. The upperportion of the frame 1 1 is provided near opposite ends with pairs of spaced lugs 18 and 20 respectively between which a longitudinally movable bolt 21 is disposed, the bolt 21 having a cross pin 22 that successively engages with the lugs 18 or 20 as the bolt is moved endwise to lift the frame 14- into a vertical position from which it be thrown downwardly by the i wei ht of the cylindrical member 17 into the position shown by full lines or the position. shown by dotted lines in Fig 2.

. The frame 14 is provided on each side with lugs 23 that engage with the insulated bars 12 and 13 to throw theswitch as the frame 14; is thrown from one position to the other.

It is apparent from the drawings that the switch blades 7 or 10 will not be disengaged from the terminals 6 or 8 with which they are in Contact until after the frame 14 has been moved into a substantially vertical position, and that when theswitch is thrown it will be moved by the weight of the cylindrical member 17 as it rolls from one end of the race 16 to the other, th s insuring that one set of contacts will be quickly broken and the other set of contacts quickly and completely closed.

In practice the bolt 21 may be any bolt that is actuated by a motor in the circuit in which the limit switch is interposed, the arrangement being such that at the end of a predetermined number of revolutions of the motor the bolt will be moved a sn'liicient disstance to cause the cylindrical member to be overbalanced and roll from one end to the other of the race 16, thereby breaking connections with one set of contacts, and making connections with another set of contacts.

For the purpose of making a momentary electrical contact as the frame la.- is thrown in one direction and avoiding the making of such momentary contact as the frame 14: is thrown in the opposite direction, a ratchet wheel 25 provided. Such wheel in the construction herein shown has four symmetrically arranged peripheral notches 26 that are each insulated from the remainder of the wheel.

Disposed between the insulated notches 26 on the periphery of the wheel are contact members 27 that may be connected with conductors 28 extending toward the center of the wheel.

- The notches 26 are adapted for the recep tion of the end of a contact spring 29 that is secured to the frame 141: so that when the frame '14; is moved from the position shown in full lines to the position shown in dotted lines in Fig. 2 the ratchet wheel will be moved tl'ierewith through an angle of Hill stantially ninety degrees and no contact between the segments 27 and the spring 29 will be made, but when the frame ll is moved from the position shown by dotted lines to the position shown by full lines in. Fig. 2 the spring 29 will ride over the peripheral surface of the wheel and will make a momentary contact with one of the segments 27 before it drops into the insulated notch next in rear of the one it occupied.

The conductors 28 may all be connected at the center of the ratchet wheel. with a common circuit wire (not shown) and the spring 29 may be connected with another circuit wire (not shown) so that when the spring 29 makes contact with one of the segments 27 the circuit will be closed.

The ratchet wheel 25 is mounted on the bolt 15 and is provided on one side with. a fixedly secured ratchet member 81. that is yieldingly held against a corresponding ratchet member 32 which is fixed on the frame 5 by a spring 33 so that the ratchet wheel cannot be rotated in a contra-clockwise direction when the frame 14 is moved from right to left as viewed in Fig. 2.

By the arrangement of parts just described it will be seen that the ratchet wheel will be advanced substantially one-fourth of one complete revolution. every time the frame I l is thrown from left to right as viewed in Fig. 2 and that the ratchet wheel will remain stationary as the frame 1-11; is thrown from right to left.

It is obvious that changes in the precise form of construction of the various parts of this limit switch may be resorted to within the scope of the appended claims.

Y lVhat we claim, and desire to protect by Letters Patent, is H 1. it switch of the class described comprising a base, a plurality of switch blades each consisting of two straight rigidly connected sections formed at an angle to each other and pivotally mounted on said base, bars of insulating material connecting the outer ends of said switch blades,.U-shaped terminals mounted on said base for the reception of the ends of said switch blades, a pivotally mounted frame adapted to swing from one side to the other of a vert' cal plane passing through its pivot point to engage with and throw said switch, a race formed in the top of said frame, a heavy roller in said race and adapted to roll from one end to the other of said race as said frame is oscillated from side to side, and means for moving said frame.

2. A switch of the class described comprising a ha e, a plurality of switch blades each consisting of two straight rigidly coir nected sections formed at an angle to each other and pivotally mounted on said in se, bars of insulating material connect ng the outer ends of said switch blades, U-shaped terminals mounted on said base for the reception of the ends of said switch blades, a l

pivotally mounted frame adapted to swing from one side to the other of a vertical plane passing through its pivot point to engage with and. throw said switch, a race formed in the top of said frame, a heavy roller in said ace and adapted to roll from one end to the other of said race as said frame is oscillated from side to side, means for moving said frame, a ratchet wheel pivoted on said base, contact members on the periphery of said ratchet wheels and means connected with said frame and adapted to make a momentary contact with said contact members only when said frame is oscillated in one direction.

3. A switch of the class described comprising a base, a plurality of switch blades each consisting of two straight rigidly connected sections formed at an angle to each other and pivotally mounted. on said base,

bars'of insulating material connecting the outer ends of said switch blades, two sets of terminals mounted on said base on opposite sides of said switch blade pivots and adapted to make contact with the ends of said blades, a frame mounted on a pivot on provided in the top said base and adapted to swing from one side to the other of a vertical plane, a race portion of said frame said race being arranged at substantially right angles to a medial plane bisecting said frame, a weight disposed to roll in said race to effect a quick throw of said frame after it passes a medial point, lugs projecting upwardly from opposite ends of said frame, a longitudinally movable bolt disposed to lie between said lugs and means on said bolt for engaging with said lugs to move said frame.

4:. A switch of the class described comprising a base, two sets of U-shaped terminals mounted thereon in spaced apart relation, switch blades pivoted between said terminals and adapted to make contact there with, said switch blades each being formed of two integral straight sections that are bent at an angle to each other so that only one end at a time of said switch blades can make contact with said terminals, a pivotally mounted frame, adapted to oscillate from a position on one side to a position on the other side of a vertical line that passes through the axis of the pivot about which such frame turns, said frame being adapted to engage with and move the said switch blades when it is oscillated to break contact with one set of terminals and make contact with another set of terminals, a race in the upper portion of said frame, a cylindrical weight adapted to roll from one end to the other of said race whensaid frame is moved from one side to the other of a vertical position, means for moving said frame, a ratchet wheel pivotally mounted 011 said base, means for preventing said ratchet wheel from turning in one direction, insulated portions in the notches of said ratchet wheel, electrical contact members on the periphery of said wheel between said insulated portions and a spring pawl connected with said frame and adapted to engage within said notches whereby when said frame is oscillated in one direction said spring pawl will move said ratchet wheel without making electrical contact therewith and when said frame is moved in an opposite direction said spring pawl will slide over the periphery of said ratchet wheel and make momentary contact with said contact members.

5. A switch of the class described, com prising an oscillating frame provided with a race in its upper portion, a weight adapted to run from one end to the other of said race, a switch adapted to be operated by the oscillation of said frame, a pivotally mounted ratchet wheel, means for preventing said ratchet wheel from turning in one direction, insulated portions in the notches of said ratchet wheel, electrical contact members on the periphery of said ratchet wheel between said insulated portions, and a spring pawl connected with said oscillating frame and adapted to engage within whereby when said frame is oscillated in one direction said spring pawl will rotate said ratchet wheel without making electrical contact with said contact members and when said frame is oscillated in an opposite direction said spring pawl will slide over the periphery of said ratchet wheel and make a momentary electrical contact with said contact members.

,6. A limit switch comprising a base, an oscillating frame pivotally mounted on said base, a rotatably mounted ratchet wheel, said ratchet wheel having insulated sections in the notches thereof, and contact conducting sections in the periphery of said ratchet wheel between each of said insulated sections, means for preventing rotation of said ratchet wheel in one direction and a spring pawl carried by said oscillating frame and engaging within the insulated notches in said ratchet wheel said spring pawl being adapted to make momentary contact with said conducting sections successively when said frame is oscillated in one direction and being adapted tg rotate said ratchet wheel when said frame is oscillated in the opposite direction. V

Signed by us at Seattle, Washington, this 29th day of May, 1918.

HENRY R. STEVENS. ROBERT L. ROCKWELL. Witnesses:

ROYAL A. MoCLURE E. G. Hown.

said notches 

